Question

What is the molarity of 34.1 g of MgS in 945 ml of solution?

a) 0.5 M
b) 1.0 M
c) 2.0 M
d) 3.0 M

Answer 1

To find the molarity of MgS, divide the mass (34.1 g) by the molar mass of MgS to get moles, convert the volume to liters, then divide moles by liters. The molarity is approximately 0.64 M, but this answer is not listed among the provided choices.

Step-by-step explanation:

Steps to Determine the Molarity of MgS

First, we need to calculate the number of moles of MgS. The molar mass of MgS (24.305 + 32.065) is approximately 56.37 g/mol. Divide the mass of MgS by its molar mass to find the number of moles:

Moles of MgS = 34.1 g / 56.37 g/mol ≈ 0.605 moles

Second, convert the volume of the solution from milliliters to liters:

0.945 L = 945 mL / 1000 mL/L

Finally, divide the number of moles of MgS by the volume of the solution in liters to find molarity:

Molarity (M) = Moles / Volume in Liters
Molarity (M) ≈ 0.605 moles / 0.945 L ≈ 0.64 M

From the options provided, none match exactly, but the closest correct answer appears to be missing from the options.